Inexpensive battery free ring sight - review lots of pics

[Mongo]

A friend of mine referred me to a thread on ARF about some inexpensive optics that were for sale on Ebay.

http://www.ar15.com/forums/t_3_18/570826_Battery_free__budget_reflex_sight.html

He said he was planning on ordering some for himself and wondered if I was interested in any. I had him get 2 for me with the knowledge that I would be experimenting on one of them so it was expendable. At the time on Ebay they were about $20 USD. The sights are NOS but the tritium has long since died in them.

There are no makers of the sight listed on it when I got it but since it was from England it was not too hard to track down.

Picture of what I received:
http://images3a.snapfish.com/232323232%7Ffp733%3C%3A%3Enu%3D3364%3E94%3B%3E2%3B7%3EWSNRCG%3D37%3C6%3C%3B7686336nu0mrj
http://images5a.snapfish.com/232323232%7Ffp6356%3A%3Enu%3D3364%3E94%3B%3E2%3B7%3EWSNRCG%3D37%3C6%3C%3B7684336nu0mrj
http://images3a.snapfish.com/232323232%7Ffp7343%3B%3Enu%3D3364%3E94%3B%3E2%3B7%3EWSNRCG%3D37%3C6%3C%3B6%3B52336nu0mrj
http://images3a.snapfish.com/232323232%7Ffp7345%3A%3Enu%3D3364%3E94%3B%3E2%3B7%3EWSNRCG%3D37%3C6%3C%3B6%3B53336nu0mrj
http://images5a.snapfish.com/232323232%7Ffp63589%3Enu%3D3364%3E94%3B%3E2%3B7%3EWSNRCG%3D37%3C6%3C%3B6%3B55336nu0mrj

They are much smaller than you think they are. I looked them up in a old 1996-96 edition of Jane's Infantry Weapons and found them. The units are manufactured by Ring Sights in the UK. Their website is http://www.ringsights.com/homepage.htm

The model is Model No. LC-7-40-M16. Here is a pdf pamphlet on the sight and how they operate. http://www.ringsights.com/Tech%20Papers/13171.PDF

This is the same company that makes the ring sight for the FN P90 PDW.

Technical Data on these supplied by Jane's

Aperture - 7mm
Focal Length - 47mm
Length - 63mm
Height - 32mm
Width - 14mm
Weight - 4g

These are designed to be mounted on the M16/AR15 carry handle.
http://images5a.snapfish.com/232323232%7Ffp63587%3Enu%3D3364%3E94%3B%3E2%3B7%3EWSNRCG%3D37%3C6%3C%3B7685336nu0mrj

The sights are solid glass in design with screw adjustment external to the optics body.
The sight has two reticules one for day time, a doughnut/ring and an open center "T" for night time. The daytime ring is white and varies in intensity based on how bright of object you are looking at though the scope. Brighter the object, brighter the ring. Being white it can be hard to pick up on certain backgrounds. The night sight "T" is powered by a tritium vial which is now dead in the sight but it also has a window on top of the sight to collect some ambient light so at those periods between light enough for the ring and not dark enough for the tritium you can see the "T". I was able to get a picture of it with a flash light illuminating it. I was unable to photograph the ring but you will see it later further down this review.
http://images5a.snapfish.com/232323232%7Ffp63585%3Enu%3D3364%3E94%3B%3E2%3B7%3EWSNRCG%3D37%3C6%3C%3B6%3B56336nu0mrj

Having two sights I was going to try to get one apart to try and replace the tritium since I have several green and red 1.5mm X 5mm vials left over from other projects where I had ordered extras.
The sight is a cast non magnetic metallic body with only the windage and elevation screws holding the assembly together. These screws are peened over at the end to retain a thick washer and are not made to be removed.
http://images5a.snapfish.com/232323232%7Ffp63592%3Enu%3D3364%3E94%3B%3E2%3B7%3EWSNRCG%3D37%3C6%3C%3B6%3B4%3B336nu0mrj
http://images5a.snapfish.com/232323232%7Ffp63558%3Enu%3D3364%3E94%3B%3E2%3B7%3EWSNRCG%3D37%3C6%3C%3B6%3B54336nu0mrj

I used a file to remove the peened over ends of the screws.
http://images5a.snapfish.com/232323232%7Ffp6356%3B%3Enu%3D3364%3E94%3B%3E2%3B7%3EWSNRCG%3D37%3C6%3C%3B7689336nu0mrj

[Mongo]

The pieces of the sight:
http://images3a.snapfish.com/232323232%7Ffp73432%3Enu%3D3364%3E94%3B%3E2%3B7%3EWSNRCG%3D37%3C6%3C%3B6%3B57336nu0mrj

The tritium square vial broke when I tried to remove it. (yes I know about the hazards and too precautions).

The stud on the bottom is a standard 5M metric thread and was Loctited in. The solid glass optics is glued to a plastic base that the windage and elevation screws pass through for the adjustments. I broke it free of the plastic base by applying a bit of pressure. No damage was done to either. It looks like some sort of Cyanoacrylate glue might have been used to secure them together.
http://images3a.snapfish.com/232323232%7Ffp73467%3Enu%3D3364%3E94%3B%3E2%3B7%3EWSNRCG%3D37%3C6%3C%3B7687336nu0mrj

I made a Solidworks model of the largest components so its easier to understand how it is assembled/works:
http://images5a.snapfish.com/232323232%7Ffp635%3A%3B%3Enu%3D3364%3E94%3B%3E2%3B7%3EWSNRCG%3D37%3C6%3C%3B6%3B48336nu0mrj
http://images5a.snapfish.com/232323232%7Ffp63599%3Enu%3D3364%3E94%3B%3E2%3B7%3EWSNRCG%3D37%3C6%3C%3B767%3B336nu0mrj
Sectioned view
http://images5a.snapfish.com/232323232%7Ffp63638%3Enu%3D3364%3E94%3B%3E2%3B7%3EWSNRCG%3D37%3C6%3C%3B6%3B49336nu0mrj

The three vials were enough to illuminate the "T" reticule but I do not think I will be able to reassemble the sight w/o making new screws for the elevation and windage. I would not buy one of these if you plan on using it with the intention of replacing the tritium in them.

The glass optic is actually four pieces of glass bonded together with black paint on areas to keep out light. Some of the surfaces are semi mirrored.
The light paths appear to be like this:
http://images5a.snapfish.com/232323232%7Ffp63562%3Enu%3D3364%3E94%3B%3E2%3B7%3EWSNRCG%3D37%3C6%3C%3B7683336nu0mrj

I took three of the spare tritium vials 1.5mm X 5mm and placed them on a piece of electrical tape.
http://images5a.snapfish.com/232323232%7Ffp63598%3Enu%3D3364%3E94%3B%3E2%3B7%3EWSNRCG%3D37%3C6%3C%3B6%3B58336nu0mrj
http://images5a.snapfish.com/232323232%7Ffp63594%3Enu%3D3364%3E94%3B%3E2%3B7%3EWSNRCG%3D37%3C6%3C%3B7688336nu0mrj

I taped them where the original vial was located and looked through the sight in a darkened room
http://images5a.snapfish.com/232323232%7Ffp63599%3Enu%3D3364%3E94%3B%3E2%3B7%3EWSNRCG%3D37%3C6%3C%3B6%3B59336nu0mrj

The ARF thread has guys placing fiber optics in the light path for the ring sight with pretty good success. I suggest you visit that thread for that work.

Picture from that thread of the ring reticule:
http://farm6.staticflickr.com/5191/7085762511_cef334bf6b_c.jpg

[Mongo]

Final thoughts:

The sight has a very small window to look through and is very cheek well dependent. For quick type shooting it might be easier to get use to once you have a lot of practice with the sight. It certainly is not as forgiving as an Aimpoint T-1 but it only cost $20 so you can't complain too much for that. I will also be trying it out with the fiber optic illumination enhancements mentioned in the ARF thread. I most likely will use it on a 22LR or something like that with a cheap ACOG clone mount.

For $20 its worth it just to play with and test it out.